1. Field of the Invention
This invention relates to dental drills and, more particularly, to dental drills which include a water distribution system for cooling purposes.
2. Description of the Prior Art
As dental drills have increased in their rotating speed, the heat caused by the friction of the high rotating speed on the teeth being worked on has required a coolant. Typically, water is used as a coolant. Typically, the water is conveyed through the dental hand piece, and specifically through the head of the hand piece. However, water droplets in high speed drills act like abrasives and cause problems with the drill, and with the various elements involved in the drill.
An example of the prior art is U.S. Pat. No. 3,762,052, the inventor of which is the inventor of the apparatus herein. In the '052 patent, water is introduced through the drill and through the burr. A combination of air pressure in centrifugal force helps to prevent water particles from entering into the bearings and other elements within the drill. However, while the '052 apparatus is an improvement over the prior art, it is still not completely effective in preventing water droplets from impinging on movable surfaces in the drill or hand piece head and of accordingly causing problems.
U.S. Pat. No. 3,778,904, the inventer of which is also the inventor herein, discloses another cooling system for dental hand piece. The '904 apparatus utilizes a stream of air as a coolant fluid, rather than water.
U.S. Pat. No. 3,871,097, the inventor of which is also the inventor of the present invention, is another improvement over the prior art. The '097 patent is a continuation-in-part of the '904 patent, and it similarly uses air as a cooling fluid.
The apparatus of the present invention utilizes water as a coolant fluid, and the water is conveyed to the drill apparatus externally of the drill itself. Water is conveyed externally of the hand piece directly to the burr of the hand piece, and the coolant water is hence delivered directly to the burr.